package com.iflysse.utils;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang.StringUtils;

/**
 * @desc: mySchedule 验证吗生成工具类
 * @author: junhan
 * @createTime: 2013年11月19日 上午9:15:29
 * @history:
 * @version: v1.0
 */
public class RandomValidateCode {
	/**
	 * 放到session中的key
	 */
	public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY";
	/**
	 * 随机数生成器
	 */
	private Random random = new Random();
	/**
	 * 随机产生的字符串的字符串范围
	 */
	private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

	/**
	 * 图片宽
	 */
	private int width = 80;
	/**
	 * 图片高
	 */
	private int height = 26;

	/**
	 * 干扰线数量
	 */
	private int lineSize = 40;

	/**
	 * 随机产生字符数量
	 */
	private int stringNum = 4;

	public RandomValidateCode() {

	}

	public RandomValidateCode(int width, int heigth) {
		this.width = width;
		this.height = heigth;
	}

	/*
	 * 获得字体
	 */
	private Font getFont() {
		return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
	}

	/*
	 * 获得颜色
	 */
	private Color getRandColor(int fc, int bc) {
		int fct = fc > 255 ? 255 : fc;
		int bct = bc > 255 ? 255 : bc;
		int r = fct + random.nextInt(bct - fct - 16);
		int g = fct + random.nextInt(bct - fct - 14);
		int b = fct + random.nextInt(bct - fct - 18);
		return new Color(r, g, b);
	}

	/**
	 * 生成随机图片
	 * 
	 * @author: junhan
	 * @createTime: 2013年11月19日 上午9:19:41
	 * @history:
	 * @param request
	 * @param response
	 *            void
	 * @throws IOException
	 */
	public void getRandcode(HttpServletRequest request,
			HttpServletResponse response) throws IOException {
		HttpSession session = request.getSession();
		// BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
		BufferedImage image = new BufferedImage(width, height,
				BufferedImage.TYPE_INT_BGR);
		// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
		Graphics g = image.getGraphics();
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
		g.setColor(getRandColor(110, 133));
		// 绘制干扰线
		for (int i = 0; i <= lineSize; i++) {
			drowLine(g);
		}
		// 绘制随机字符
		String randomString = "";
		for (int i = 1; i <= stringNum; i++) {
			randomString = drowString(g, randomString, i);
		}
		session.removeAttribute(RANDOMCODEKEY);
		session.setAttribute(RANDOMCODEKEY, randomString);
		g.dispose();
		// 将内存中的图片通过流动形式输出到客户端
		ImageIO.write(image, "JPEG", response.getOutputStream());

	}

	/*
	 * 绘制字符串
	 */
	private String drowString(Graphics g, String randomString, int i) {
		g.setFont(getFont());
		g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
				.nextInt(121)));
		String rand = String.valueOf(getRandomString(random.nextInt(randString
				.length())));
		g.translate(random.nextInt(3), random.nextInt(3));
		g.drawString(rand, 13 * i, 16);
		return randomString + rand;
	}

	/*
	 * 绘制干扰线
	 */
	private void drowLine(Graphics g) {
		int x = random.nextInt(width);
		int y = random.nextInt(height);
		int xl = random.nextInt(13);
		int yl = random.nextInt(15);
		g.drawLine(x, y, x + xl, y + yl);
	}

	/*
	 * 获取随机的字符
	 */
	public String getRandomString(int num) {
		return String.valueOf(randString.charAt(num));
	}

	/**
	 * 验证验证码的正确性并删除session
	 * 
	 * @author: junhan
	 * @createTime: 2013年11月19日 上午11:28:13
	 * @history:
	 * @param req
	 * @return boolean
	 */
	public static boolean vaildRand(HttpServletRequest req, String inputName) {
		String rand = (String) req.getSession().getAttribute(RANDOMCODEKEY);
		String input = req.getParameter(inputName);
		 req.getSession().removeAttribute(RANDOMCODEKEY);
		if (StringUtils.isEmpty(rand)) {
			return false;
		}
		if (StringUtils.isEmpty(input)) {
			return false;
		}
		if (!input.equalsIgnoreCase(rand)) {
			return false;
		}
		return true;
	}

}